AG 1343 is a well-absorbed inhibitor of HIV-1 protease that has demonstrated potent antiviral activity in vitro and in vivo. This study is designed to continue to test three different dosage schedules of AG 1343 for both activity and safety in those patients who experienced a 90% reduction in viral load during the first 28 days of therapy. Participants will be monitored monthly for evidence of drug efficacy and toxicity. Patients who demonstrate an increase in their viral load while on AG 1343 monotherapy will be allowed to initiate therapy with additional FDA- approved nucleoside analogues.